Multiple fluid pump



p 1969 c. L. PRITCHARD ETAL 3,467,016

MULT IPLE FLUID PUMP Filed Sept. 15, 1967 2 Sheets-Sheet 1 I NVENTORS CL 5 L; PENN/4K0 CAR YLE 0. T ff ATTOKNEVS United States Patent US. Cl. 103-9 22 Claims ABSTRACT OF THE DISCLOSURE A multiple fluid pump having a resiliently elastic diaphragm for pumping fluids in a first pumping chamber, closed 01f by the diaphragm, and in a second pumping chamber provided at the periphery of the diaphragm. The central portion of diaphragm is reciprocated to pump a first fluid through the first pumping chamber. When the material of the diaphragm is intermittently squeezed between the arm and the resistance of the fluid in the first chamber, a portion of the diaphragm material intermittently bulges into the second pumping chamber to pump a second fluid. Both pumping chambers communicate with inlet and outlet check valves. Alternate forms are described in which the second chamber is formed entirely within the diaphragm, entirely within the pump housing, and in both. Further forms are shown having additional pumping chambers transversely spaced across the periphery of the diaphragm and peripherally spaced around the diaphragm.

Background of the invention-This invention relates to a multiple fluid pump, and more particularly to a pump of the diaphragm type in which the pumping of one fluid is dependent upon the presence of another fluid.

Pumps of this type are frequently used in situations such as oil-fired boilers, where it is desirable to control the flow of fuel oil to the burner in accordance with the flow of water to the heating coils, in order to terminate oil flow immediately and positively upon cessation of water flow from the feed pump. Should fuel oil continue to be supplied and ignited in the absence of water flow from the feed pump, the coils may be damaged, or an explosion may even result. If the fuel oil is supplied and not ignited, unburned fuel accumulates in the vicinity of the burner, and may ignite or detonate upon the next ignition of the burner.

The principal problems encountered in constructing failsafe apparatus for fuel flow cutoff lie in the areas of sensitivity, speed, and reliability. Prior devices have been complex in construction to achieve the sensitivity and speed necessary for safe operation, and yet the complexity itself rendered such devices inherently more subject to failure. When applied to water heating apparatus subject to repetitive short-term demand, such as portable steam cleaners, otherwise minor defects in the operation of the failsafe devices were aggravated by the large number of cycles of operation to which they were subjected.

Summary of the invention.The pump of the present invention interlocks and proportions the pumping of one fluid to the pumping of another by using the resistance of the first fluid to being pumped to create the pumping force for the second fluid. When the resistance of the first fluid to movement of the diaphragm is not present, the force of the stroke is not transmitted to the second fluid.

The first pumping chamber is formed by a reciprocated diaphragm closing off a cavity in the pump housing, and the pumping chamber of the second pump is formed at or near the rim of the same diaphragm, and is likewise Patented Sept. 16, 1969 closed ofl by the material of the diaphragm. The first fluid is pumped when the diaphragm is reciprocated by an arm on a crankshaft. Part of the material of the diaphragm is displaced laterally and bulges into the second chamber to displace the second fluid when the diaphragm is squeezed between the arm and the resistance of the fluid in the first pumping chamber.

When the countering force of the fluid in the first pumping chamber is lessened or entirely absent, the material of the diaphragm is not displaced as much laterally, and the pressure transmitted to the fluid in the second pumping chamber through this lateral displacement is greatly reduced or eliminated. The proportional relation between the fluid pressure in the first pumping chamber and the amount of fluid pumped through the second chamber may also be used to proportion the rate of supply of the second fluid in accordance to the rate of supply of the first. For example, fuel oil may be supplied to the burner of a water boiler in accordance with the demand for the water, or an additive, such as a detergent solution may be supplied in proper proportion to the water flow.

Accordingly, it is a principal object of the present invention to provide a single-diaphragm pump of the character described which is capable of simultaneously pumping two or more separate fluids.

It is a further object of the present invention to provide a single-diaphragm multiple fluid pump of the character described in which the pumping of the second fluid is physically dependent upon the presence of the first fluid in the pump.

Another object of the present invention is to provide a multiple fluid pump of the character described which will positively and reliably halt the supply of the second fluid upon a pressure drop in the first fluid.

Yet another object of the present invention is to provide a multiple fluid pump of the character described which utilizes a minimum of parts and which is simple in operation to enhance its reliability.

Still another object of the present invention is to provide a pump of the character described providing a safety interlock between fuel supply and water supply for a fuel-burning water heating apparatus.

A further object of the present invention is to provide a failsafe safety interlocked fuel and water supply system for water heating and steam generating apparatus capable of positively halting fuel supply upon a drop in water pressure.

Further objects and advantages of the present invention will become apparent as the specification progresses, and the new and useful features thereof will be fully defined in the claims attached hereto.

Brief description of the drawings.-The preferred form of the invention is illustrated in the accompanying drawings, forming part of this application, in which:

FIGURE 1 is a view taken partially in cross-section through the pump of the present invention.

FIGURE 2 is an enlarged fragmentary cross-sectional view taken approximately along the same plane as FIG- URE 1, showing the diaphragm at the midpoint of the stroke.

FIGURE 6 is a cross-sectional view taken approximately along a plane parallel to the diaphragm and passing through its transverse center, showing yet another form of the invention.

While only the preferred forms of the present invention are shown here, it should be understood that various changes or modifications may be made within the scope of the claims attached hereto without departing from the spirit of the invention.

Description of the preferred embdiments.The pump 11 of the present invention includes a housing 12 formed to provide a cavity 13 and a flexible diaphragm 14 of resilient material mounted in the housing 12 across the cavity 13 to define a first pumping chamber 16, the central portion of the diaphragm 14 being adapted for connection to a reciprocating means 17 for alternately increasing and decreasing the volumetric capacity of the first pumping chamber 16 so as to create a pumping action. A second pumping chamber 18, at the peripheral portion of the diaphragm 14, is formed so that the pressure pulses of the reciprocating means 17 urging the diaphragm 14 toward the first pumping chamber 16 against the resistance of a fluid contained in the first pumping chamber 16 will intermittently displace a portion of the diaphragm 14 into the second pumping chamber 18 for alternately increasing and decreasing its volumetric capacity so as to create a pumping action.

The diaphragm 14 may be formed of any suitable elastic material of high resistance to deterioration, such as synthetic rubber. The diaphragm 14 here is relatively thick in proportion to its diameter, and is firmly sealed at its periphery to the housing. Conveniently, the sealing is accomplished by adhesion through bonding, such as at 19 in FIGURE 2, and by physically gripping the diaphragm in serrations 21 formed along the confronting faces of flanges 22 formed on the housing 12. Other techniques of sealing may be used, but any such technique should be able to withstand a very large number of flexures at several hundred pounds of fluid pressure, and a considerable amount of lateral tension.

The second pumping chamber 18 as shown in the embodiment of FIGURES 1 through 4 is provided by a groove 23 in the periphery of the diaphragm 14 and a complementary groove 24 formed in that portion 26 of the housing 12 lying between the flanges 22. Alternatively, the second pumping chamber could be formed by either groove 23 or groove 24 alone, but grooving both the housing and the diaphragm has been found to be advantageous. The second pumping chamber 18 communicates with a passageway 27 in housing portion 26 leading through a conduit 28 to a T connector 29. A one-way inlet check valve 31 is located in an inlet conduit 32 leading from a source of fluid (not shown) into the T 29 and a one-way outlet check valve 33 is located in an outlet conduit 34 leading from the T 29. These check valves prevent back flow of fluid, permitting the alternation in volume of the second pumping chamber 18 to create a pumping action. It should, of course, be appreciated that the second pumping chamber 18 could be provided with separate inlet and outlet passages, each equipped with the appropriate one-way check valves, instead of the single passageway 27 and the T arrangement 29.

The reciprocating means 17 may be of any suitable type and includes an eccentric crankshaft 36 journaled in the housing 12, and an arm 37 journaled on the crankshaft 36. The arm 37 terminates adjacent the diaphragm 14 in a shoe 38. The center of the diaphragm 14 is attached to the shoe 38 by a bolt 39, so that rotation of the crankshaft 36 reciprocates the diaphragm 14 toward and away from the first pumping chamber 16. The first pumping chamber 16 is equipped with inlet and outlet check valves 42 and 43, respectively, for preventing backflow of the first fluid and to provide the desired pumping action. Appropriate backpressure may be maintained in the first pumping chamber 16 by having the outlet check 4 valve 43 spring-biased toward the closed position, or by locating suitable orifices or other flow control devices the discharge line (not shown) downstream of the first pumping chamber 16.

An example of the behavior of the periphery of the diaphragm 14 during reciprocation, when fluid pressure is present in the first pumping chamber 16, is shown in FIG- URES 3 and 4. In FIGURE 3, the arm 37 is shown alt the bottom of a downstroke, or intake stroke. Fluid flows into the first pumping chamber 16 through the inlet check valve 42 and into the second pumping chamber 18 through the conduit 27 during the intake stroke. As the diaphragm moves up through the upstroke to the position shown in FIGURE 4, the fluid in the first pumping chamber 16 is subjected to pressure to pump it. At the same time, the material of the diaphragm 14 is com pressed between the upward force of the shoe 38 and the resistance, or backpressure, of the fluid in the first pumping chamber 16, illustrated schematically by the arrows 41. In response to this compression, the material of the diaphragm engages in elastic flow laterally, toward the second pumping chamber 18. As may be seen in FIGURE 4, the material of the diaphragm 14 bulges into the second pumping chamber 18, moving from the position shown in dotted lines in that figure to the position shown in solid lines. The described bulging reduces volumetric capacity and applies pressure to the fluid in the second pumping chamber 18, causing it to flow out of the chamber through the conduit 28 and thus create the pumping action for the second fluid.

When no fluid is present in the first pumping chamber 16, the backpressure schematically represented by the arrows 41 is absent, and the material of the diaphragm 14 is not forced to fiow laterally by compression to the same degree. Some lateral flow, and hence pressure on the second pumping chamber 18, may still occur. However, the overall pump 11 may be made to differentiate between the presence and absence of fluid backpressure in the first pumping chamber 16 by appropriate selection of the backpressure imposed upon the second pumping chamber 18. For example, the outlet check valve 33 for the second pumping chamber 18 may be made spring-loaded toward the closed condition, or another biased valve (not shown) may be interposed downstream of the second pumping chamber 18 to provide such backpressure. The force applied to the fluid in the second pumping chamber 18 will then necessarily have to exceed the backpressure imposed before fluid will be pumped by the second pumping chamber.

It may be seen that the shoe 38 acts to enhance the lateral movement of the material of the diaphragm 14 when the latter is under compression, by evenly distributing the upward pressure of the arm 37 over the major part of the lower surface of the diaphragm 14. The diaphragm is thus forced by the two opposing pressures to displace in the lateral direction.

In FIGURE 5, an alternate embodiment of the pump of the present invention is shown, in which the diaphragm 14 is formed with two transversely spaced peripheral grooves, and the housing portion 26 is grooved correspondingly, so that two separate pumping chambers 18a and 18b are formed at the periphery. Passageways 27a and 27b, respectively, lead to conduits 28a and 28b, respectively. The periphery of the diaphragm 14 is bonded to the housing as noted above in connection with the embodiment of FIGURES 1 through 4, and is additionally bonded to the housing, as shown at 19a, between the two grooves to keep the pumped fluids separate.

The embodiment shown in FIGURE 6 is similar to that shown in FIGURE 5 except that the two peripheral grooves are spaced from each other around the periphery. Two pumping chambers, 18c and 18d, respectively, are thus formed, with each of the pumping chambers extending for only a part of the periphery of the diaphragm 14. Appropriate inlet and outlet conduits and inlet and outlet check valves, numbered as in the first embodiment but shown in FIGURE 6 with c and d suflixes to the numbers, are provided. Similar conduits and check valves are provided for the embodiment of FIGURE 5, but are omitted from the figure for clarity. The embodiments of FIGURES and 6 operate in the same fashion as the first embodiment, and allow the pumping of two fluids to be made dependent upon the fluid backpressure in the first pumping chamber 16.

It should be appreciated that although only two peripheral pumping chambers have been illustrated in the embodiments of FIGURES 5 and 6, further grooves or other cavities transversely spaced across the peripheral edge of the diaphragm could be used to form additional pumping chambers, or additional cavities extending for only part of the perimeter of the diaphragm could be formed, with each cavity occupying an appropriate fraction of the periphery, rather than a complete annular track. Alternatively, the second pumping chamber 18 could be formed similar to one shown in FIGURE 6, but with the chamber lying entirely within the diaphragm, pocket-fashion, and communicating by a necked-down passageway with the periphery of the diaphragm.

Both the peripheral extent of the cavity and its width and depth may be selected to give the desired proportion of output between the first pumping chamber 16 and any additional chambers 18. The size of the pocket in the pocket-type embodiment mentioned above may likewise be chosen to give the desired output ratio between the first pumping chamber and the second pumping chamber. When multiple grooves are used as in the embodiments of FIGURES 5 and 6, the pumping chambers at the periphery may be used to pump dilferent fluids, or they may be ganged together in various combinations to produce additional pumping capacity for one of the fluids. Considerable versatility in the ratio of pumping capacities between the first pumping chamber 16 and the additional chambers may thus be achieved.

A typical range of working pressures for a pump 11 as shown here, when applied to a water heating apparatus, might be considerably in excess of 100 pounds per square inch gauge, say in the neighborhood of 400 pounds per square inch gauge, for the water pumped by the first pumping chamber 16, and slightly less than 100 pounds per square inch gauge, say around 40 to 80 pounds per square inch gauge, for the fuel oil pumped to the burner by the second pumping chamber 18. A bleeder valve 44 allows air to be vented from the second pumping chamber to prime the pump.

From the foregoing, it may be seen that a simple and reliable single-diaphragm pump has been provided for pumping two separate fluids with the pumping of the second fluid being dependent upon the backpressure of the first fluid, so that the supply of the second fluid is positively and reliably halted immediately upon a pressure drop in the first fluid. The pump forms a simple and reliable interlock between water and fuel supply to enhance the safety of operation of a fuel-fired water heating apparatus.

We claim:

1. A pump, comprising a housing formed to provide a cavity,

a flexible diaphragm of resilient material mounted in said housing across said cavity to define a first pumping chamber, the central portion of said diaphragm being adapted for connection to reciprocating means for alternately increasing and decreasing the volumetric capacity of said first pumping chamber so as to create a pumping action, and

a second pumping chamber at the peripheral portion of said diaphragm formed so that the pressure pulses of said reciprocating means urging said diaphragm toward said first pumping chamber against resistance of a fluid contained therein will intermittantly displace a portion of said diaphragm into said second pumping chamber for alternately increasing and decreasing its volumetric capacity so as to create a pumping action.

2. A pump as described in claim 1 and wherein said pump includes inlet and outlet check valves communicating with said first pumping chamber for preventing backflow of the fluid pumped therethrough and inlet and outlet check valves communicating with said second pumping chamber for preventing backflow of the fluid pumped therethrough.

3. A pump as described in claim 1 and wherein said second pumping chamber is formed by a groove in the periphery of said diaphragm.

4. A pump as described in claim 3 and wherein a complementary groove is formed in said housing confronting said groove in the periphery of said diaphragm.

5. A pump as described in claim 4 and wherein said groove extends in annular fashion about the periphery of said diaphragm.

6. A pump as described in claim 1 and wherein said second pumping chamber is formed by a groove in said housing confronting the periphery of said diaphragm.

7. A pump as described in claim 1 and wherein said diaphragm is formed with a plurality of spaced annular grooves in the periphery thereof for pumping a plurality of fluids in addition to the fluid pumped by said first pumping chamber.

8. A pump as described in claim 1 and wherein said diaphragm is formed with a plurality of grooves in the periphery thereof, with each groove extending for only a part of the periphery of said diaphragm.

9. A pump as described in claim 4 and wherein said diaphragm is formed with a plurality of spaced annular grooves in the periphery thereof for pumping a plurality of fluids in addition to the fluid pumped by said first pumping chamber.

10. A pump as described in claim 4 and wherein said diaphragm is formed with a plurality of grooves in the periphery thereof, with each groove extending for only a part of the periphery of said diaphragm.

11. A pump as described in claim 5 and wherein said diaphragm is formed with a plurality of spaced annular grooves in the periphery thereof for pumping a plurality of fluids in addition to the fluid pumped by said first pumping chamber.

12. A pump as described in claim 5 and wherein said diaphragm is formed with a plurality of grooves in the periphery thereof, with each groove extending for only a part of the periphery of said diaphragm.

13. A single-diaphragm multiple-fluid pump, comprising a housing having walls providing a cavity,

a diaphragm of elastic material sealed to said housing adjacent the periphery of said diaphragm to close off said cavity and define a first pumping chamber, said diaphragm cooperating with said housing to define a second pumping chamber adjacent the periphery of said diaphragm and sealed ofl? from fluid communication with said first pumping chamber, and

means for reciprocating said diaphragm toward and away from said first pumping chamber to pump a first fluid therethrough, reciprocation of said diaphragm against the resistance offered by said first fluid causing elastic flow of the material of said diaphragm toward and away from said second pumping chamber, thereby oscillating the volume of said second pumping chamber to pump a second fluid therethrough.

14. A pump as described in claim 13 and wherein said pump includes inlet and outlet check valves communicating with said first pumping chamber for preventing backflow of the fluid pumped therethrough and inlet and outlet check valves communicating with said second pumping chamber for preventing backflow of the fluid pumped therethrough.

15. A pump as described in claim 13 and wherein said second pumping chamber is formed by a groove in the periphery of said diaphragm.

16. A pump as described in claim 15 and wherein a complementary groove is formed in said housing confronting said groove in the periphery of said diaphragm.

17. A pump as described in claim 13 and wherein said second pumping chamber is formed by a groove in said housing confronting the periphery of said diaphragm.

18. A safety interlocked fuel and water supply system for water heating and steam generating apparatus having fuel and water supplies, comprising a single-diaphragm pump for both the fuel and the water, said pump comprising a housing formed to provide a cavity,

a flexible diaphragm of elastically resilient material mounted in said housing across said cavity to provide a water pumping chamber,

a reciprocating means adapted for connection to the central portion of said diaphragm for periodically increasing and decreasing the volume of the water pumping chamber to create a pumping action for the water, and

a fuel pumping chamber at the peripheral portion of said diaphragm formed so that the pressure of said reciprocating means urging said diaphragm toward said water pumping chamber against the resistance of the water will periodically displace a portion of said diaphragm laterally and into said fuel pumping chamber for periodically increasing and decreasing its volume to create a pumping action for the fuel dependent upon the resistance of the water.

19. A pump as described in claim 18 and wherein said pump includes inlet and outlet check valves communicating with said water pumping chamber and inlet and outlet check valves communicating with said fuel pumping chamber for preventing backflow of water and fuel.

20. A pump as described in claim 19 and wherein said output check valve communicating with said fuel pumping chamber is spring-biased toward a closed position to create a backpressure in said fuel pumping chamber, whereby fuel will not be pumped in the absence of a force due to the lateral displacement of said diaphragm exceeding said backpressure.

21. A pump as described in claim 19 and wherein said fuel pumping chamber is formed by a groove in the periphery of said diaphragm and a groove in said housing confronting said groove in the periphery of said diaphragm.

22. A pump as described in claim 21 and wherein said grooves are annular and extend around the entire periphery of said diaphragm.

References Cited FOREIGN PATENTS 943,739 6/ 1956 Germany. 1,191,302 4/1959 France. 1,215,012 11/1959 France.

20,471 8/ 1929 Netherland.

HENRY F. RADUAZO, Primary Examiner US. Cl. X.R. 103-148, 

